Carbohydrates (Part 3)

Question 0

Hexokinase reagents and products

Answer 0

Reagent: hexokinase and glucose-6-phosphate dehydrogenase
Products: glucose6-phosphate and 6-phosphoglyconate +NADPH + H

Question 1

A two step reaction that is proposed to be the reference method when a protein-free filtrate is used

Answer 1

Hexokinase

Question 2

The first step of hexokinase is ________ while the second is ________

Answer 2

specific; non-specific

Question 3

absorbance in hexokinase is measure at ________

Answer 3

340 nm

Question 4

A two-step reaction with the first step being specific and the second, non-specific; good method for serum, plasma, urine, and csf; o-dianisidine is the chromogen

Answer 4

Glucose oxidase; “trinder”

Question 5

Glucose Oxidase “Trinder” reagents

Answer 5

glucose oxidase; peroxidase

Question 6

Plasma glucose reference interval

-Adults

Answer 6

70-100 mg/dL

Question 7

Plasma glucose reference interval

-children

Answer 7

70-100 mg/dL

Question 8

Plasma glucose reference interval

-preemies

Answer 8

25-80 mg/dL

Question 9

Plasma glucose reference interval

-term babies

Answer 9

60-95 mg/dL

Question 10

CSF glucose reference interval

Answer 10

60-70% of concommitant plasma levels

Question 11

Patient preparation instructions for an oral glucose tolerance test (OGTT)

Answer 11

1 minimum of 150 g CHO for 3 days prior to test
2 fasting for 10-16 hrs (water only)
3 discontinue medications that alter glucose levels
4 normal amount of activity before and during test

Question 12

Three indications for performing an intravenous glucose tolerance test

Answer 12

malabsorption, sprue (Celiac Disease), GI surgery

Question 13

can be used for preliminary diagnosis of diabetes mellitus; give 75 g oral glucose load or have patient eat a meal; 2 hours later if glucose is _____ may be diabetic

Answer 13

Postprandial Testing; >126 mg/dL

Question 14

used to diagnose gestational diabetes, performed at _____to_____ weeks gestation; give _____ g glucose load to fasting patient and draw sample at 1 hour; if ____mg/dL perform OGTT

Answer 14

O’Sullivan Test; 24-28 weeks; 50g; >140 mg/dL

Question 15

ESSAY

metabolic pathway that leads to ketone body formation

Answer 15

formed from Beta-oxidation of free fatty acids

Question 16

ESSAY

Name three ketone bodies and their specific relative proportions in the blood

Answer 16

1 Beta-hydroxybutyric acid (78%)
2 Acetoacetic acid (20%)
3 Acetone (2%)

Question 17

ESSAY

Specific starting points of ketone bodies

Answer 17

*pyruvate, amino acids, and fatty acids

Question 18

Three processes that lead to ketosis due to patients deficiency of glucose

Answer 18

decreased sodium, decreased bicarbonate, and decreased blood pH

Question 19

Why does patient develop acidosis and hyperlipidemia?

Answer 19

The body is using fatty acids as energy in hyperlipidemia.

Increased in free ketone bodies produce excess H+ ions in acidosis.

Question 20

Five conditions of decreased CHO availability that can lead to ketosis

Answer 20

starvation, frequent vomiting, glycogen storage diseases, alkalosis, and alcoholism

Question 21

ESSAY

Specific reagent used in colorimetric method (Acetest or Ketostix)

Answer 21

Sodium nitroprusside

Question 22

ESSAY

Specific relative reactivity with each of the three ketone bodies in the colorimetric method

Answer 22

Reacts ONLY with acetone and acetoacetate; five times more sensitive to acetoacetate; does NOT react with beta hydroxybutyrate

Question 23

ESSAY

specimen storage requirements for the colorimetric method (Acetest/Ketostix)

Answer 23

Keep container closed and keep refridgerated

Question 24

Describe the pathogenies of hyperosmolar hyperglycemic nonketonic coma (HHNC)

Answer 24

- occurs in older patients - Increased blood glucose (no ketosis) - Increased osmolality - Intracellular dehydration - cellular edema in brain

Question 25

Three causes of Type A lactic acidosis

Answer 25

Decreased tissue oxygenation from: - shock - hypovolemia - cardiac failure

Question 26

5 causes of Type B lactic acidosis

Answer 26

Metabolic causes associated with disease (DM, neoplasia, liver diseases) or dug/toxins (alcohol, salicylates)

Question 27

5 causes of increased CSF lactate

Answer 27

1. CVA 2. Intracranial hemorrhage 3. Bacterial meningitis (normal in viral) 4. Epilepsy 5. Other CNS disorders

Question 28

Patient preparation, specimen collection, and sample analysis requirements for lactate

Answer 28

- no tourniquet - no exercising of arm - must be placed on ice IMMEDIATELY - separate from cells within 15 minutes of draw

Question 29

Essay? | describe the process of glycation

Answer 29

Glycation is the non-enzymatic addition of a sugar residue to amino groups of protein

Question 30

Essay? Why can the measurement for glycated hemoglobin be used to assess diabetic blood sugar control over a three to four month at a time span?

Answer 30

Since glycated hemoglobin formation is irreversible AND the normal RBC lifespan is 120 days, these tests assess diabetic compliance with therapy for the preceding 120 days! Levels are unaffected by day-to-day fluctuation, exercise, etc

Question 31

Essay? | Two general categories of glycated hemoglobin measurement methods

Answer 31

1. Methods based on charge differences | 2. Methods based on structural differences

Question 33

Specific clinical application of measuring: | - Insulin

Answer 33

Evaluates fasting hypoglycemia; not necessary to measure to diagnose diabetes mellitus

Question 34

Specific clinical application of measuring: | - Proinsulin

Answer 34

Evaluates patients with benign or malignant beta-cell tumors of pancreas

Question 35

Specific clinical application of measuring: | - C-Peptide (3)

Answer 35

Evaluates fasting hypoglycemia, insulin-producing beta-cell tumors, response to pancreatic surgery

Question 36

Specific clinical application of measuring: | - Urine glucose

Answer 36

Uses glucose oxidase to produce color change; specific for glucose only

Question 37

Specific importance of urinary albumin and miroalbumin measurements in predicting diabetic nephropathy

Answer 37

persistent proteinuria is the best indicator for renal disease and can be used to screen diabetics for nephropathy development

Question 38

Importance of urinary micro albumin excretion

Answer 38

It precedes nephropathy and is a marker for mirovascular disease!